Many mobile and stationary machines employ drive systems that transmit mechanical energy from an input end to an output end for performing various tasks. Where control of certain drive system output parameters (e.g., speed, torque, direction of rotation or travel, etc.) is desired, mechanical devices, such as gearboxes, are commonly connected between the input end and the output end of the drive system. A gearbox typically includes a number of components that work together to transmit power, such as gears, shafts, and bearings that are protected from their surroundings in a sealed container. A gearbox typically requires constant lubrication to reduce friction and keep the internal components cool during operation. As the components wear and/or fail over the useful life of a gearbox, they can shed debris particles that accumulate in the lubricant and necessitate periodic repairs and/or lubricant replacement.
Repairing or replacing a gearbox requires that the associated machine be temporarily taken out of service, which can decrease productivity. One way to reduce loss of productivity is to predict when a gearbox is going to fail and to perform periodic maintenance prior to failure. To predict gearbox failures and facilitate planning of future gearbox maintenance, manufacturers have implemented gearbox monitoring systems. Some gearbox monitoring systems predict the lifespan of gearboxes using mathematical functions. In particular, the mathematical functions predict future wearing of components based on historic data and current gearbox operating parameters. However, variations in operating conditions, component flaws, load variances, unexpected failures, and other inconsistencies may cause known gearbox monitoring systems to produce inaccurate estimations of gearbox lifespan.
One attempt to estimate the lifespan of a gearbox is described in U.S. Pat. No. 7,914,250 (the '250 patent) that issued to Behera et al. on Mar. 29, 2011. The '250 patent describes a gearbox lifespan estimation system that includes a number of sensors associated with various shafts, gears, and bearings within a gearbox. The sensors generate field data, such as a number of start-ups, load sequences, oil quality, vibrations, component speeds, and the power output of the gearbox. The field data is used in a model to simulate the total power input to the gearbox and the individual loads experienced by each gearbox component due to the load input. The field data is also used in an algorithm for determining physical faults associated with the gearbox components, such as cracked or broken gear teeth and bearing damage. The faults are used to estimate additional loads experienced by the individual gearbox components caused by the faults. A total load on each component is then estimated by summing the load caused by the input power to the gearbox and the load caused by the faults. The lifespan of the gearbox is estimated to be the shortest lifespan of the individual components based on the total estimated loads.
Although the system of the '250 patent may be somewhat effective at determining the lifespan of a gearbox, it may not be optimum. In particular, the system of the '250 patent may determine the gearbox lifespan based only on estimated loads of the gearbox, which may render the lifespan estimation inaccurate when the estimated loads are themselves inaccurate. Further, the system of the '250 patent may not be able to determine when the models and algorithms used to estimate the gearbox lifespan are inaccurate or correct their inaccuracies.
The gearbox monitoring system of the present disclosure solves one or more of the problems set forth above and/or other problems of the prior art.